Search

Alphafetoprotein is at present the only 'antigen' of proved clinical value in gynaecological neoplasia. Its synthesis and release by a particular type of germ cell tumour (yolk sac, endodermal sinus tumour) present alone or as part of a teratoma approaches many of the essential criteria of a utopian tumour marker. Unfortunately, none of the other recognised 'antigens' expressed and/or released by gynaecological tumours and which have been adequately assessed in the clinical situation, seem to represent laboratory adjuncts essential for adequate patient care at present. Further research is needed to define other factors if this approach to improving diagnosis and management is to succeed.

The pathologic features of the primary tumors in 285 patients with breast cancer at the time of initial presentation, and with no clinical evidence of distant metastases, have been analyzed. The results have been compared with the detection of tumor cells in the bone marrow by use of an immunocytochemical method using antisera raised against the epithelial membrane antigen (EMA). The authors found EMA-positive cells (i.e., tumor cells) in the bone marrow of 77 (27%) patients and a significant association between the presence of such EMA-positive cells in the bone marrow and tumor size (P = 0.006) and peritumoral vascular invasion (P = less than 0.001). A possible relationship with estrogen receptor negativity (P = 0.06) also was noted.

N-Methyl-N-nitrosourea (MNU) given iv to rats 50-55 days old induced mammary tumors in 70% of F344/N and 91% W/ICRF inbred females with mean latency periods of 149 and 93 days, respectively. Reduction of the MNU dose did not affect tumor incidence in W/ICRF rats. Of the mammary tumors, 98% were classified histologically as adenocarcinomas, which grew progressively. Primary tumors of nonmammary origin were detected at low incidence. Upon histologic examination, no evidence was found for metastases of either the mammary or other primary tumors. No evidence for tumor-induced hypercalcemia was found. Oophorectomy at the time of MNU administration prevented tumor development; oophorectomy when at least 1 tumor/animal was palpable caused growth delay or regression. All MNU-induced and 7,12-dimethylbenz[a]anthracene-induced mammary tumors tested contained cytoplasmic estrogen receptor (ER) at similar concentrations and were indistinguishable histologically. MNU-induced tumors in F344 rats were transplantable and retained ER through three transplantations.

SUMMARY A virilizing interstitial cell tumour and the attached testicular tissue from a 4-year-old boy were incubated in vitro with [7α-3H]pregnenolone and [4-14C]progesterone, or [4-14C]androstenedione and [7α-3H]5α-dihydrotestosterone. Ring A saturated steroids were produced from 4-ene precursors by the prepubertal testis, but this tissue was unable to convert pregnenolone or progesterone to 17α-hydroxylated C21 steroids, or to C19 steroids. The virilizing interstitial cell tumour metabolized pregnenolone and progesterone to 17α-hydroxyprogesterone, androstenedione and testosterone. In addition, dehydroepiandrosterone was detected as a product of pregnenolone. The tumour lacked 4-ene-5α-steroid reductase activity. 5α-Dihydrotestosterone was metabolized to 5α-androstane-3,17-dione, androsterone, isoandrosterone, 5a-androstane-3α,17β-diol and 5α-androstane-3β,17β-diol in both the normal and tumour tissue. The significance of these metabolic pathways is discussed.

SUMMARY The metabolism of [7α-3H]dehydroepiandrosterone (DHA) and [4-14C] androstenedione in vitro was investigated in 30-day-old (prepubertal) and adult rat testicular tissue in the presence of cyanoketosteroid, a 5-ene-3β-hydroxysteroid oxidoreductase inhibitor. Whereas both substrates were converted to 5α-reduced steroids by the prepubertal testis, 4-ene-steroid-5α-reductase activity was negligible in the adult gland. Cyanoketosteroid prevented the formation of 5α-reduced steroids from DHA by the prepubertal testis indicating testosterone and androstenedione as intermediates in their production.

Publisher Summary This chapter discusses tissue culture's role in some selected chemical, pathological, and fundamental aspects of the endocrinology of both steroid and peptide hormone-secreting tissues. Tissue culture has many forms; none is easy and many are both time-consuming and laborious. In some respects, they still represent art forms with a complexity that defies simple analysis. The chapter describes some of the reasons why this has occurred. If, however, tissue culture is to achieve preeminence in experimental studies, its days as an art rather than a science must be numbered. Certain basic problems of methodology, however, still remain to be solved by systematic experimentation, leading ultimately to the preservation of complete structural and functional integrity of purified endocrine cells in culture under completely defined conditions. Further progress in the use of tissue culture to study functional activity and growth may be considerably hampered until these requirements are fulfilled. It would be foolhardy to suppose, however, that there exists one all-encompassing ideal medium or system of culture, and conditions may have to be optimized for each individual cell type or tissue, particularly for human material. Failure to contend with these and similar problems may serve to further perpetuate the myth of culture being inevitably associated with radical changes in the behavior of cells and tissues. A further goal must also be dispensing with the use of serum to sustain cultured cells, as many of the complications that beset endocrine cultures in particular stem from its use. Although efforts in this direction are being made, much remains to be discovered about the precise role played by serum in cultures and the way by which it can be replaced by defined constituents.

SUMMARY Quantitative aspects of corticosteroidogenesis were examined in monolayer cultures of cells from the zona fasciculata and zona reticularis of the adult rat adrenal cortex, maintained for up to 4 months. Corticosterone secretion continued at a steady rate in cultures maintained with corticotrophin (ACTH), the output of maximally stimulated cultures being approximately 12 μg/106 adrenocortical cells/day. In the absence of ACTH, a small amount of 20α-hydroxypregn-4-en-3-one, but no detectable corticosterone, was secreted, resulting in a fluorogenic steroid output 1/125 th of that of maximally stimulated cultures. Restimulation with ACTH of cultures maintained for up to 2 months in its absence resulted in maximum levels of corticosterone secretion after 4–5 days of continuous ACTH treatment. The levels of corticosterone secretion attained on restimulation were similar to those observed in cultures maintained with ACTH from the out set. Withdrawal of ACTH resulted in a fall in steroid output which took 10 days to reach final unstimulated levels. Trophic stimulation of corticosteroidogenesis with a similar time-course was obtained with both cyclic AMP and dibutyryl cyclic AMP, the latter being the more effective.

SUMMARY Incubation in vitro of homogenates of spontaneous adrenocortical tumours from gonadectomized female mice of the CE strain showed the presence of Δ5-3β-hydroxysteroid dehydrogenase systems, capable of metabolizing 3β-hydroxypregn-5-en-20-one, 3β, 17α-dihydroxypregn-5-en-20-one and 3β-hydroxyandrost-5-en-17-one. 17α-, 11β- and 21-hydroxylation of C21-Δ4-3-ketosteroids was also detected as were the enzyme systems required to form 3β-hydroxyandrost-5-ene-7,17-dione from 3β-hydroxyandrost-5-en-17-one. After tissue culture of the tumour cells for 19 days, histochemical and incubation techniques demonstrated that the cells retained Δ5-3β-hydroxysteroid dehydrogenase, 17α-, 11β- and 21-hydroxylase activity. Autoradiography localized radioactivity in the original and newly formed cells of the tissue culture.

SUMMARY Confluent monolayer cultures of cells from the zona fasciculata and zona reticularis of the normal adult rat adrenal cortex were maintained with or without corticotrophin (ACTH) for up to 4 months, without proliferation of adrenal cells. Proliferating fibroblast-like cells, however, eventually overgrew the adrenal monolayer in cultures both with and without ACTH. Adrenocortical cells in culture, maintained without ACTH, spread rapidly to form a confluent monolayer, whereas cell spreading was markedly inhibited in the presence of ACTH. Exposure of previously unstimulated cells to ACTH or cyclic AMP caused the adrenal cells to retract with loss of confluence, the process being reversed when ACTH or cyclic AMP was withdrawn. Ultrastructural features of cells cultured with ACTH were typical of normal adrenocortical cells; in cultures without ACTH they were similar to those of adrenocortical cells found in the hypophysectomized rat.

SUMMARY The patterns of exogenous steroid metabolism by rat adrenocortical zona fasciculata and zona reticularis cells cultured together as a monolayer have been examined. In the continued presence of corticotrophin (ACTH), the cultured cells synthesized corticosterone, 18-hydroxydeoxycorticosterone and deoxycorticosterone from [3H]pregnenolone. In the prolonged absence of ACTH, however, [3H]pregnenolone was metabolized mainly to progesterone, 20α-dihydroprogesterone, 20α-hydroxy-5α-pregnan-3-one and 5α-pregnane-3β,20α-diol with small amounts of 5α-pregnane-3,20-dione, 11β-hydroxyprogesterone and 11β-hydroxy-20α-dihydroprogesterone, while virtually no corticosterone, 18-hydroxydeoxycorticosterone or deoxycorticosterone were produced. While 5-ene-3β-hydroxysteroid dehydrogenase-isomerase activity persisted at a substantial level in unstimulated cells and the 11β- and 18-hydroxylases were reduced but still present, 21-hydroxylase activity was almost completely lost when ACTH was omitted from the culture medium. These changes in enzyme activities were completely reversed by the addition of ACTH, cyclic AMP or dibutyryl cyclic AMP to unstimulated cultures for 4–5 days, during which time no proliferation of adrenal cells was observed.